Just start cutting the air near their head. Did that once, guy finally looked up and said "you know what, surprise me." Real power move. Honestly, after two minutes I just set my timer. The silent buzz from my pocket is my cue to say "we gotta pick one." They're always paralyzed by choice.
In my experience, you gotta have a go-to move for this. I usually start scrolling through my own phone, like I'm checking a text or an email. Another thing is to just focus on your own stuff, maybe clean your glasses or fix your hair in a mirror. If it drags on, a light comment like "lots of options, huh?" can nudge them along. Your mileage may vary, but having a few distractions ready saves your sanity.